Machines for boring and finishing cylindrical holes such as engine cylinder bores use a tool having abrasive strips mounted on a cylindrical body. As these tools wear, they are generally adjusted radially outward to compensate for the depletion of the abrasive surface. The wear compensating adjustment mechanism forms part of the tool body and comes in many shapes and sizes for example the tool shown and described in U.S. Pat. No. 4,075,794. These tools consist of a mandrel which connects to the machine spindle at one end and is constructed with an abrasive head at the other. A connecting rod connects to an adjustment mechanism within the abrasive head to bias the abrasive elements radially outward against the work piece. The adjustment can be accomplished automatically as shown in the '794 patent or manually as shown in the reference Gross, U.S. Pat. No. 2,787,865.
The problem with tools of this type is that they are complex mechanisms which have to be continuously removed from the machine spindles for repairs, replacement of abrasives and maintenance. Each time this occurs, an expensive part of the machine is unproductive. It requires skill and care to make sure that the tool mechanism is properly installed. Since the tool assembly of the prior art may weigh between 15 and 20 pounds, servicing of this element becomes a significant effort and is awkward for a single operator to accomplish.
It is the purpose of this invention to provide a tool body which is removable from the mandrel in a convenient and reliable manner to allow maintenance of the abrasive elements without extensive effort. The tool body of this invention significantly reduces the weight which needs to be handled during servicing or replacement of the abrasive elements and this tool body is a much less expensive part to replace than comparable parts in the prior art. Removal of the tool body of this invention can be accomplished without disconnecting the air gauge as required in prior art systems. This avoids contamination thereby improving accuracy, and saving time.